The administration of Afatinib will start on Day 3 of each therapy cycle with an administration interval on each weekend ("Weekday on, Weekend off") for 21 days. Instructions are given on the dose reduction scheme in the presence of toxicity. The administration of the combination Cisplatin-5FU-Afatinib will be continued until disease progression, appearance of significant toxicity, completion of 6 treatment cycles, or withdrawal of consent. At completion of 6 cycles of the combination, in the absence of disease progression, the administration of Afatinib as maintenance monotherapy will be continued until disease progression, appearance of significant toxicity, or withdrawal of consent at the weekday on-weekend off schedule. Imaging will be applied once every 8 weeks, and once every 12 weeks in the Afatinib maintenance therapy phase.